This invention relates to a device for securing a non-magnetic sheet material and more particularly relates to securing of materials such as paper and thin card stock of a thickness less than about one millimeter.
Numerous devices and methods for securing sheets of material are well known including tapes, adhesives, clipping devices such as found on clip boards, tacks, rings such as found in ring binders, and magnetic holders such as “refrigerator magnets”. All of these devices have disadvantages including one or more of difficulty and time required for use, destruction or modification of the sheet material surface or even the integrity of the material itself, injury to the substrate to which the sheet is held, inability of reuse, complexity and expense, requirement for special, e.g. bulletin board or magnetic, substrates, insufficient holding power, inability to simultaneously organize a plurality of sheets on a surface and loss of integrity or breakage over a short sequence of uses even when reuse is possible.
Use of Bingo cards is one particular example needing low expense, simplicity, speed of use, holding power, ability to organize a plurality of sheets, requirement for non-injury to the substrate or sheet, and frequent repetitive use without breakage. Historically, Bingo cards were taped to a table requiring time, wasting tape, and causing injury to the card and often to the table.
U.S. Patent Publication US 2004/0135315 A1 published Jul. 15, 2004, provides an example of an improved device for securing and organizing Bingo cards. The device is made from a single plastic sheet to which is attached a ferromagnetic strip and a magnetic strip such that when the plastic sheet is folded, a non-magnetic sheet material can be held or clamped between the ferromagnetic strip and magnetic strip. The device, nevertheless has serious disadvantages. In particular, after repeated use, the plastic material will crack at the fold to permit the ferromagnetic strip and magnetic strip to approach each other. Furthermore, the magnetic strip is not at the edge of the plastic sheet thus causing both the magnetic strip and a portion of the plastic sheet to obscure a significant portion of a retained non-magnetic sheet. To overcome this serious disadvantage, the device of US 2004/0135315 A1 prints the “BINGO” bingo card top line designations on the device. Unfortunately, this requires time consuming and annoying precise alignment with the card and since all cards are not of exactly the same size, such alignment is not always possible. Furthermore, such printed designations prevent the device from being practically used when sheet material other than bingo cards are to be secured.